Question: If you walk on a dry path between two walls a few feet apart, you hear a musical note or “ring” at each footstep. Whence comes this?Answer: This is similar to phosphorescent paint. Once any sound gets between two parallel reflectors or walls, it bounds from one to the other and never stops for a long time. Hence it is persistent, and when you walk between the walls you hear the sounds made by those who walked there before you. By following a muffin man down the passage within a short time you can hear most distinctly a musical note, or, as it is more properly termed in the question, a “ring” at every (other) step.

Our atom of carbon enters the leaf, colliding with other innumerable (but here useless) molecules of nitrogen and oxygen. It adheres to a large and complicated molecule that activates it, and simultaneously receives the decisive message from the sky, in the flashing form of a packet of solar light; in an instant, like an insect caught by a spider, it is separated from its oxygen, combined with hydrogen and (one thinks) phosphous, and finally inserted in a chain, whether long or short does not matter, but it is the chain of life. All this happens swiftly, in silence, at the temperature and pressure of the atmosphere, and gratis: dear colleagues, when we learn to do likewise we will be sicut Deus [like God], and we will have also solved the problem of hunger in the world.

Levi Primo and Raymond Rosenthal (trans.), The Periodic Table (1975, 1984), 227-228. In this final section of his book, Levi imagines the life of a carbon atom. He calls this his first literary dream. It came to him at Auschwitz.

We do not draw conclusions with our eyes, but with our reasoning powers, and if the whole of the rest of living nature proclaims with one accord from all sides the evolution of the world of organisms, we cannot assume that the process stopped short of Man. But it follows also that the factors which brought about the development of Man from his Simian ancestry must be the same as those which have brought about the whole of evolution.

In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
(1987) -- Carl Sagan